The 6-Channel Line Input Module S3-ISR .
This module is a 6 channel line input module that can be used for surround sources, as a 6 channel return unit or as a sub group master for surround groups. The S3-ISR fits into a normal channel slot. Any number of theses modules can be installed but there are no group buss amp integrated.

Analog surround mixing in combination with a digital audio workstation requires a lot of channels, if no submix is made inside the DAW. The best compromise between performance gain by using single converters for every track and the total cost of the analog surround console is to single out the least important tracks and combine these tracks to a surround submix using the mixing system of the DAW. The real important tracks are fed thru converters to separate channels. With this common principle there has to a way to include 6 channel sub-groups from the DAW into the analog mix without using 6 mono channels for every surround sub-group. The solution for this requirement is the S3-ISR line input module.

All the available connectors of a standard channel slot are used for the six inputs of the device. To keep the cost for this module a low as possible we abandoned the idea of integrating any kind of surround processing equipment. For this reason there is an input gain control with a range of +/- 20 dB with a calibrated center detent and 6 additional pots for the adjustment of the level balance between the six channels. These control have a range of +/- 12 dB each.

Six separate PFL controls make it possible to easily monitor each channel separately. An additional PFL 'All' switch routes the summed channels to the PFL buss. As PFL is stereo system, the 'All' functions works like a simple stereo downmix matrix and sends the 'front left' and 'surround left' channels to the left PFL channel and the 'front right' and 'surround right' channels to the right PFL channels. The levels of the surround channels are reduced by 3 dB. The center channel feeds both the PFL channels with a level of - 3 dB each. The LFE channel is also included and drives both of the PFL channels at 0 dB but with a fixed limit frequency of 80 Hz.

The fader section is a 6 channel VCA fader that is controlled by a 100 mm slider fader. The maximum gain of the fader section is 10 dB. A computer interface section is included as well as selector for the 4 combined VCA and CUT-Groups. The CUT functions mutes all the channels. There is no difference between the S3-ISR and the mono channel in the operation of the Solo system.

For level control there are 6 peak present multicolor LED next to the PFL switches. These indicator show a level of more than - 20 dB green and change the color to yellow at a level of 0 dB. With an increase of the level the color changes to orange and reaches red at a level 3 dB below clipping.

The MIX-OFF switch isolates the output of the fader section from the main surround mix bus.